Mechanical Engineer

The Opportunity

Lumai is redefining how the world computes. We are an ambitious, venture-backed UK startup pioneering a breakthrough AI accelerator for data centers which uses 3D optical compute. Our radical technology uses light to perform computation at orders of magnitude faster speeds and at far greater scales than ever before, all whilst consuming far less energy than traditional approaches.

Lumai is unlocking performance and efficiency gains that could transform the economics of AI and compute infrastructure and reshape how intelligence scales globally.

If you are passionate about bringing groundbreaking technology to market, and want to be part of a team pushing the boundaries of what is physically possible, Lumai is where you can make it happen.

Founded in 2022, Lumai is a University of Oxford spinout using optical processing to accelerate large language models (LLMs) and other transformer-based AI systems. The team combines expertise in optical computing, machine learning, and physics.

Lumai has already secured over $15 million in investment from leading deep-tech investors like Constructor Capital, IP Group, Photon Ventures and government grants, and is scaling rapidly to deploy the fastest optical compute currently available globally.

We are seeking a skilled Mechanical / Optomechanical Engineer to join our Oxford-based team. The ideal candidate will be responsible for designing, analysing, and improving mechanical systems and components for our product. The role involves collaborating with cross‑functional teams to develop innovative solutions that meet project objectives and industry standards. We welcome applicants both from earlier career and more experienced engineers.

What You'll Do

• Conceptualise, design, and develop compact, robust optomechanical systems for products, prototypes and optical testing. Develop optical mounting and alignment techniques working with the optical team
• Work with the optical and electronics teams to produce system prototypes
• Utilise CAD software to create detailed designs and engineering drawings
• Conduct structural, material, and thermal analysis to optimise the performance and reliability of optomechanical systems
• Participate in prototype builds, testing, and validation of optomechanical systems to ensure compliance with design specifications and performance requirements

• Manage multiple projects simultaneously, ensuring adherence to deadlines and budget allocation
• Coordinate with internal teams and external stakeholders to define project requirements and deliverables
• Monitor project progress, identify potential risks, and implement mitigation strategies as needed

• Prepare detailed documentation, including design specifications, technical reports, and project documentation
• Communicate project status updates, technical findings, and recommendations to key stakeholders
• Maintain accurate records of design iterations, test results, and project-related documentation

Must-Have

• Effective communication and interpersonal skills
• Undergraduate or master’s degree in mechanical engineering or related field
• Minimum of 2 years of experience in mechanical design and analysis
• Strong understanding of mechanical principles, and materials science
• Proficiency in CAD software (e.g., Solid Works, AutoCAD) and simulation tools (e.g., ANSYS)
• Ability to work independently and collaboratively in a fast‑paced environment

Strong Preference For

• Experience with optical products (e.g. projector, microscopes, Lidar, laser systems etc)
• Knowledge and practical experience of optomechanical system design
• Familiarity with the basic principles of optical design is desirable, but not essential
• Proficiency in structural simulation tools (e.g. ANSYS)
• Experience in taking technology from concept, to prototype, to product

• Highly Competitive Salary: We are not saying our salary is a blank check, but let's just say it won't be a source of your stress
• Share Option Scheme: We are all in this together! We believe in shared success while we build the Lumai of tomorrow
• Pension Scheme: Plan for…